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Multiple intracardiac recordings in evaluation of patterns occurring during attempted his bundle pacing in man
Insights
This study analyzed intracardiac electrograms during His bundle pacing in 30 patients. It clarifies pacing patterns and differentiates impulse origins, enhancing understanding of complex cardiac activation sequences.
Area of Science:
- Electrophysiology
- Cardiac Pacing
- Arrhythmia Diagnosis
Background:
- Understanding His bundle pacing is crucial for cardiac rhythm management.
- Intracardiac electrograms provide detailed insights into cardiac electrical activity.
Purpose of the Study:
- To evaluate pacing patterns from His bundle stimulation.
- To differentiate between His bundle pacing and other pacing sites using electrograms.
- To enhance the understanding of complex cardiac activation during pacing.
Main Methods:
- Intracardiac electrograms recorded from multiple sites (RVA, LV, HRA, LA) in 30 patients.
- Stimulation through catheter electrodes to induce His bundle activity.
- Analysis of stimulus-to-ventricular intervals (St-V, St-RVA, St-LV) and comparison with sinus beats (H-V, H-RVA, H-LV).
- Evaluation of retrograde atrial activation intervals.
Main Results:
- His bundle pacing showed specific interval patterns matching sinus beats.
- Right septal pacing resulted in a left bundle branch block pattern with distinct intervals.
- Fusion beats exhibited characteristics of both His bundle and septal activation.
- Retrograde atrial activation intervals differentiated pacing origins.
Conclusions:
- Simultaneous recording of atrial and ventricular electrograms aids in interpreting His bundle pacing patterns.
- This analysis improves differentiation of pacing sites and understanding of cardiac activation.
- Findings contribute to more precise cardiac pacing strategies and diagnosis.
Abstract:
The various patterns resulting from stimulation through the catheter electrodes recording His bundle activity were evaluated in 30 patients using intracardiac electrograms from the right ventricular apex (RVA), posterosuperior wall of the left ventricle (LV), high right atrium (HRA) and left atrium (LA) in the vicinity of the coronary sinus. His bundle pacing was characterized by a QRS complex and stimulus (St)-V, St-RVA and St-LV intervals that equated the QRS configuration, H-V, H-RVA and H-LV intervals of sinus beats. Right septal pacing produced pattern of "complete" left bundle branch block (with normal electrical axis) associated with St-V intervals of 0 msec, and St-RVA and St-LV intervals of different duration from that of the H-RVA and H-LV intervals recorded during sinus rhythm. Fusion beats resulting from simultaneous activation of His bundle and right septal muscle were characterized by St-V intervals of 0 msec and St-RVA or St-LV intervals of similar duration to that of the H-RVA or H-LV intervals of sinus beats. Fusion QRS configuration depended on the type of ventricular complex present during sinus rhythm. Analysis of the retrograde atrial activation intervals permitted differentiation among impulse initiation at the low right atrium, His bundle or right septal muscle. Simultaneous recording of multiple atrial and ventricular electrograms has enhanced understanding of the complex patterns observed during attempted His bundle pacing in man.